Charterhouse Square School is an independent, non-selective, co-educational day school with 200 children aged 3 to 11, situated in the Barbican area of the City of London. It occupies a five-story Victorian building overlooking Charterhouse Square near what used to be a Carthusian monastery.

Charterhouse is a member of Cognita Schools, an association of independent schools in UK and overseas. Despite sharing a similar name, it is not affiliated or related to Charterhouse School, a public boarding school which was originally founded near the square before moving to its current location in Godalming, Surrey.

The ages given are guidelines only. When deciding on a year group, the school's policy is to look at the child's ability as opposed to their date of birth. Any child who is performing academically and socially above expectations has the opportunity to skip a class (subject to a place being available).[2]